COMPARATIVE VALUE OF EXCITING SOLUTIONS. 



51 



How often Solutions should be Changed and Zinc Amalgamated* 



Students have often put this question to us : " How often should 

 the solution in the cell be renewed, and the zinc plate be amalga- 

 mated ? " The following are the results of many trials made to 

 ascertain the facts necessary to answer this inquiry. The zinc plates 

 used were nearly one foot square, and the copper plate upon which 

 the deposit was made was of the same size as the zinc plates. 



In the first series the zinc plates were not taken out either to 

 brush or re -amalgamate, neither were the solutions renewed during 

 the time specified. 



